pp料應用介紹:
聚丙烯塑料的改性可分為化學改性和物理改性兩種方法。化學改性主要通過共聚、接枝、交聯等方式, 改變聚丙烯的分子結構以達到改性的目的; 物理改性則在整個改性過程中不發生化學反應, 在PP基體中加入其他無機材料、有機材料、其他塑料、橡膠、熱塑性彈性體或有特殊功能的添加助劑等, 經過共混、增強或填充等手段制得具有優異性能的PP復合材料。
注塑工藝參數對pp料塑料熔體表觀黏度的影響:
聚丙烯( PP) 屬于結晶性高聚物,有著質輕、無毒、價廉、耐高溫等優點,在醫藥、食品、汽車和化工等領域中有著廣泛的用途。PP 是典型的熱塑性塑料之一,自從米蘭理工大學的G. Natta 教授發現等規聚丙烯以來,全球的聚丙烯工業迅速發展,現今產量僅次于聚乙烯。注塑成型能夠一次成型外形復雜、尺寸或帶有嵌件的塑料制品,是塑料加工的主要方法之一。塑料熔體的表觀黏度可以指導擬定注塑工藝,也能夠指導模具型腔設計和優化流道澆注系統。
大量現貨hi828注塑級
Rheological Properties of Flame Retardent and Antistatic Polypropylene Material
WANG Shuai 1,2, WANG Kejian 1*, MA Yi 2*, ZHANG Yinling 2, LIANG Wenbin 2,WANG Xu 1,SHI Jiao 1,JIANG Zhuoyu 1
(1 College of Mechanical and Electrical Engineering, Beijing University of Chemical and Technology, Beijing 100029,China;2 National Institute of Clean and Low Carbon Energy,Beijing 102211,China)
Abstract: The effects of brominated flame retardant and carbon black-filling on the extrusion distortion of PP melt and dynamic rheological properties were investigated by capillary rheometer and rotational rheometer. It was shown that the more filled resin exhibited higher critical shear rate for extrusion distortion corresponding to wider processing window in low filler content range. In dynamic rheometry, the higher filled resins behavior in shear thinning with higher complex viscosity,storage modulus and loss modulus instead of lower loss factor. Quantitative analyses were conducted using entanglement model and Cross model. Filler can absorb polymer chains reducing wall adsorption dropping distortion and further resulting in higher critical shear rate. Particle filled network increases in the plateau modulus and entanglement density shortening relaxation time for quicker recovering according to smaller extrusion swell ratio. Carbon black more than 3.5wt% in composite forms percolation network being characterized by higher zero shear viscosity and longer relaxation time where liquid-solid-like transition occurs. Simultaneously, the surface resistivity decreased obviously. The viscoelastic percolation value consistent with the electrical percolation value approximately.
Keywords: Rheology; polymer; particle; composites; extrusion distortion; percolation network
。大量現貨hi828注塑級
pp顆粒原料特點:
特點:無毒、無味,密度小,強度、剛度、硬度耐熱性均優于低壓聚乙烯,可在100度左右使用.具有良好的電性能和高頻絕緣性不受濕度影響,但低溫時變脆、不耐磨、易老化.適于制作一般機械零件,耐腐蝕零件和絕緣零件 。常見的酸、堿有機溶劑對它幾乎不起作用,可用于食具。
車用pp顆粒改性介紹:
改性PP 的氣味組成及形成:改性PP 材料的氣味主要來源于材料的揮發性有機化合物(VOC),其組成可以通過氣相色譜– 有機質譜聯用儀、頂空法等方法進行分析。羅忠富通過氣相色譜–質譜對車用PP 復合材料氣味進行了分析研究。結果發現,PP 材料的揮發性氣體組分有近20 種,主要由羰基化合物與烴類化合物組成,并且在這些組分中,羰基化合物如酮、醛與酯比烴類化合物能產生更明顯的氣味。
大量現貨hi828注塑級
D.射出初胚重量按15-2%抽檢,精胚重量偏重的,要求返工到合格為止,重量偏輕的,予以剔除。E.定型個人計量表數字必須準備,字跡清楚,不得涂改,填表人與主管依必須相應的欄目下簽名以示負責。F.定期檢測初胚重量用的電子稱。定型單位工作須知::.量產中的定型模具每個月必須復核一次,所有模具每三個月須由技術單位復核一次。B.定型模具不足三塊時,不的進行定型生產。C.無量產之模具須清理干凈后,整齊放置于模具架上,且有明確標識。